What is the primary function of the sheath in a grass leaf?

The primary function of the sheath in a grass leaf is to protect the blade. The sheath is the part of the leaf that wraps around the stem of the plant, anchoring the leaf in place and providing structural support. This protective role is essential, as it helps shield the more delicate blade from physical damage and environmental stressors such as wind and mechanical wear. By encasing the base of the blade, the sheath also aids the plant in directing nutrients and water that flow up from the roots to the blade where photosynthesis occurs. While other functions are important in different parts of the plant—such as water absorption, photosynthesis, or nutrient storage—the sheath’s primary role is focused on protection and support for the blade.